Burglar-alarm door-lock.



C. McDADE & F.'CHAPMAN.

BURGLAR ALARM 000R LOCK memo! Hm; m 26. m1.

Patented May 7,1918.

' V 2 MEETS-SHEET I.

Iv-mm T Lginruzn/ c. McD'ADE & F CHAPMAN. BUHGLAR ALARM DOOR LOCK. APPLICATION FILED MAY25| 9|?- 1,265,?Q2a Patented May 7,1918.

2 SHEETS-SHEET 2.

PATENT OFFICE- CLARENCE McDADE, 0F MIDDLEPORT, OI-IIO, AND FRANK CHAPMAN, OF HARTFORD, WEST VIRGINIA.

BURGLAR-ALABM DOOR-LOCK.

Specification of Letters Iatent.

Patented May '7, 1918.

To all whom it may concern:

Be it known that we, CLARENCE MCDADE and FRANK CHAPMAN, citizens of the United States, residing, respectively, at Middleport and Hartford, in the counties of Meigs and Mason, States of Ohio and West Virginia, have invented a new and useful Burglar-- Alarm Door-Lock, of which the following is a specification.

The subject of this invention is a burglar alarm door lockin which an alarm is embodied in and forms part of a door knob, and the objects of the invention are, first, to provide a combined door knob and burglar alarm, second, to provide a spring aetuated door knob released alarm, provide a latchfor locking the door and setting the parts in position to operate,*fourth, to provide a simple and efficient burglar alarm.

NVith the foregoing and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of invention herein disclosed can be made within the scope of what is claimed, without departing from the spirit of the invention.

A practical embodiment of the invention is shown in the accompanying drawings, wherein:

Figure 1 is a view in elevation of a portion of a door showing, in side elevation, a knob constructed in accordance with our invention in place thereon.

Fig. 2 is a vertical, central longitudinal section of the knob, a portion broken away;

Fig. 3 is a top plan view of the knob, one end broken away.

Fig. 4 is an end elevation of the knob with the end section and central plate re moved.

Fig. 5 is a cross section on the line 5 -5 of of Fig. 2.

Referring to reference: 1

An outer knob 1 of the usual form is provided, and this knob has a shaft 2 projecting therefrom. The shaft 2 is formed with a reduced, elongated cylindrical end 3 to the end of which is secured a cam plate 4.

The inner knob has a shaft 5 extending the drawings by numerals of third, to

therefrom and this shaft is provided with a central longitudinal bore 6 which receives, and in which turns the cylindrical end 3. A slot 7 is formed in the shaft 5 adjacent the inner knob, and this slot alines with a socket 8 formed in the portion 3, when the portion 3 is in one position. Ears 9 are formed on the shaft 5, and a double ended latch 10 is pivotally secured between the ears and rocks in one direction to enter the slot 7 and socket 8 and lock the shaft 5 to the reduced end 3 of shaft 2, when the latch 10 is rocked in the other direction its opposite end enters a slot 11 formed in a door plate 12 which surrounds the shaft 5 and is secured to the door in the usual manner.

The inner knob is formed of two sections.

One section 13 is in the form of a half knob, being a hollow convex member preferably integral with the shaft 5. The knob portion 13 is formed with a slight offset 14 rising from a point on the rear of its outer surface. The offset 14 has a vertical bore formed therein and communicating with the interior of the knob member 13. A pin 15 reciprocates in this here and is normally held in its elevated position by a coiled spring 16 which surrounds the pin and is confined between the ofiset 14 and a button 17 secured to the upper end of the pin.

' The interior of the knob member 13 is formed with a flat face 18 at the portion from which the shaft projects. Spaced slightly from this face 18 are inwardly projecting lugs 19 which form a seat for a'division plate 20, which plate is secured to the lugs by screws 21, or otherwise. At the rim of the knob member 13 are spaced, inwardly projecting lugs 22 to which is secured a plate 23, by screws 24 or otherwise.

Secured to the center of plate 23, and extending horizontally therefrom is a hollow supporting post 25, the central longitudinal bore of which alines with an aperture formed in the center of the plate 23. Another knob member 26, which is a bell, is secured as shown or otherwise secured to the end of the post 25. A shaft 27 passes through the post 25, in which it turns and its inner end is journaled in the Plate 20. A spur gear 28 has a ratchet engagement with the shaft 27 on which it is mounted between the plates 20 and 23 and a sprin 29 surrounds the shaft 27 and has one en secured to the shaft and the other end secured to the plate 23, in the usual and well known manner.

A shaft 30 extends between the plates 20 and 23, in which it is journaled, and a pinion 31 is secured on the shaft and adapted to mesh with the gear 28. A spur gear 32 is also mounted on the shaft 30 and is locked against turning by a latching bar 33 which extends through a slot formed in the plate 20 and is pivotally secured between ears 34 which are formed on the plate 20. The latching bar is thrown to locking position by depression of the pin 15, the inner end of which contacts one end of the latching bar and the baris unlatched by the cam plate 4 coming in contact with one end thereof.

Extending between and journaled in the plates 20 and 23- is a rock shaft 35, from which extends an angular arm 36 bearing on its end a knob 37 and forming a clapper for the bell 26. A cross arm 38 is secured on the shaft 35 and its angularly disposed ends are positioned to be alternately struck by the teeth of the spur gear 32 to rock the shaft and oscillate the clapper. A knurled thumb piece 39 may be provided on the outer end of the shaft 27 for the purpose of turning the same to wind the spring.

While the device has been described as containing an alarm, it is understood that the alarm may be left out and regular knobs substituted, the latch 10 being retained to lock the outer knob against turning.

In practice the device is operated in the following manner :The mechanism in the inner knob is removed inprder to secure the device to a door. The cam plate is removed from the end 3 of shaft 2 and the end 3 inserted in shaft 5, which shaft has been placed in position in the lock. The cam plate is then fastened in place and the other parts of the inner knob assembled. When the knob is to be used as an ordinary knob, the latch 10 is swung into position within the slot 7 and socket 8. This locks the shafts against revolution with respect to each other. When the alarm is to be used, the pin 15 is depressed to throw the latching bar into enga 'ement with the teeth of gear wheel 32 and lock the wheel against motion. spring 29 is now wound through the shaft 27 and its thumb piece 39, in the usual manner. The latch 10 is then thrown to engage Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents The the slot 11 in door plate 12 which locks the shaft 5 against turning and releases the shaft 2 and its extension 3 from locked engagement with the shaft 5. If the outside knob should now be turned, the cam plate 4 would be revolved to contact the end of latching bar 33 and disengage it from the gear wheel 32. The gearing is now free to turn under the expansive force of the spring 29 and will cause the clapper to oscillate and ring the bell, in the usual and well known manner.

Having described our invention, what we claim as new and desire to secure by Letters- Patent, is

1,. A burglar alarm door knob, comprising an inner and outer knob, a shaft on the inner knob provided with a longitudinal bore, a shaft on the outer knob adapted to turn in the bore, means for normally locking the shafts against relative revolution, a cam on the inner end of the shaft of the outer knob, and means actuated by revolution of the cam for sounding an alarm.

2. A burglar alarm door knob, comprising a knob, a spindle projecting from the knob and provided with a socket, a cam plate secured to the end of the spindle, another knob, ahollow shaft projecting from the knob and surrounding the spindle, said hollow shaft provided with a slot alining with.

the socket, a latch pivotally secured to the hollow shaft and swinging in one direction to enter the slot and socket and lock the shaft and spindle together and in the opposite direction to lock the hollow shaft and its knob against rotation, a spring actuated gear train in the last mentioned knob, means for winding the spring, a clapper oscillated by the gear train, and a latch bar for looking the gear train against motion and relelasing the train when contacted by the cam p ate.

In testimony that we claim the foregoing as our own, we have hereto aflixed our signatures in the presence of two witnesses.

CLARENCE McDADE. FRANK CHAPMAN. V'Vitnesses as to McDade:

H. O.'ALEXANDER, W. ARMSTRONG. Witnesses as to Chapman:

NEWTON MCKNIGHT, H. D. CHAPMAN.

Washington, D. C. 

